Respected teachers / mates ,
please help me ... any reference or explanation will be helpful.. what do u understand by the following paragraph which has been taken from harper 28th edi pg 220.. i am very confused ..
in adipose tissueIncreased Glucose Metabolism Reduces the Output of Free Fatty Acids
When the utilization of glucose by adipose tissue is increased, the free fatty acid outflow decreases. However, the release of glycerol continues, demonstrating that the effect of glucose is not mediated by reducing the rate of lipolysis. The effect is due to the provision of glycerol 3-phosphate, which enhances esterification of free fatty acids. Glucose can take several pathways in adipose tissue, including oxidation to CO2 via the citric acid cycle, oxidation in the pentose phosphate pathway, conversion to long-chain fatty acids, and formation of acylglycerol via glycerol 3-phosphate . When glucose utilization is high, a larger proportion of the uptake is oxidized to CO2 and converted to fatty acids. However, as total glucose utilization decreases, the greater proportion of the glucose is directed to the formation of glycerol 3-phosphate for the esterification of acyl-CoA, which helps to minimize the efflux of free fatty acids.
now since u have read this let me put my doubt ...
it appears that if glucose metabolism is directed towards syn of glycerol3 phosphate the certainly FFA being released from adipose cell will decrease while glycerol will continued to be secreted since lipolysis will not be decreased but lipogenesis is increased due to increased concentration of glcerol 3 phoshphate which will react with released FFA and form monoacyl then diacyl then triglycerides
now in next few lines harper says that if glucose utilization is higher then a larger uptake proportion is oxidised to CO2( means more energy generation) and formation of acyl CoA (means more FFA synthesis) which should actually lead to increased output of FFA from adipose cells whuch is contradictory to intial concept
and again in last line harper says the total opposite as total glucose utilization decreases the greater proportion of the glucose is directed to the formation of glycerol 3-phosphate for the esterification of acyl-CoA which helps to minimize the efflux of free fatty acids.
everything seems to be correct
what is going on here... please help ....